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This could be a little project that we can all chip in to get made, a better save board for the G-Net :)
 
I can do this! Give me a little bit.

Edit: Have to wait for the camera battery to charge apparently!
 
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So basically its a capacitor charging/discharging circuit. I wonder why they chose to go this route instead of just using a battery. The only advantage I see is the faster charging/discharging of the caps over batteries.
 
So basically its a capacitor charging/discharging circuit. I wonder why they chose to go this route instead of just using a battery. The only advantage I see is the faster charging/discharging of the caps over batteries.
This is what the original Xbox did too. they had an Aerogel Cap that would hold charge for about 3 days for the system clock... when it was still new it was a really cool concept, but it seems really foolish in retrospect.

I'm more interested in a permanent, non-battery solution.
 
I'm more interested in a permanent, non-battery solution.
This would be ideal.

I guess we would need to figure to where the G-NET is storing saves, etc... and see if that circuit can be modified to a non- battery solution. It appears all this board does if provide enough power for an operator to move the game to another location or for it to be shut-off overnight or something.
 
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well that's me confused, i expected an extra memory device!
so all we really need to work out is the pinout of the connector and then create something using 18650's ripped from laptop packs. :D
 
but yes, fitting ferroram or something would be better - but most people cant swap smd chips.
 
Curious, can you take a pic or let us know the rating of the 3 large caps?
2.5V 4.7f

If anyone who has the skills/interest/whatever needs one in order to work toward a project that would benefit everyone, I'll gladly lend mine out.
 
those caps are in series, so it's actual value is 7.5v 1.5F
and it has balance resistors across them that will cause them to self-discharge!!
 
that makes sense because the board has to sit between the main power rail and the ram - if you didnt have a way to isolate the ram powerlines the backup board would try to power the entire pcb!
 
what would be helpfull, get a volt meter and check the voltage on each of the 6 pins both running and then in powered-off / backup state.

see what voltage the ram needs and what pins it's on, and what the "charge" voltage is.
 
OK - I've checked my two G-Net PCB's and this is the pattern I'm seeing - apologies for the crap photo's.

For PCB's without the backup PCB fitted (with or without the pins at "P").

No backup unit:-
JP1 - Open
JP2 - Open
JP3 - Closed (either a link or closed jumper).
JP4 - Open

DSC04924 (Medium).JPG


With backup unit:-
JP1 - Open
JP2 - Closed
JP3 - Open
JP4 - Closed

DSC04923 (Medium).JPG


Can someone check they have the same jumper settings - Also the circle with the two holes in looks like it could be for a battery (as it's labelled B+ on one side - maybe that's a simpler solution). This PCB also has an extra component at L5 but as it's been repaired (caps have been replaced) I don't know if it's factory.
 
Mine has no backup unit, and it's just like yours. JP3 is closed with a link, but all the rest are open.
 
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